A compact array of four bottom-mounted pressure sensors arranged in a square, a slope array, is frequently used to obtain estimates of the wave radiation stresses in shallow water. For wavelengths long in comparison with the array dimension (L), existing processing methods (Higgins et al., 1981) have bias errors of O(kL)2, with k the wavenumber. An estimator for wave radiation stresses and energy fluxes is derived here that reduces the bias to O(kL)4, thus considerably extending the frequency range of accurate estimates of a slope array. The stability of the new estimator to statistical fluctuations in the cross spectra is similar to the method of Higgins et al. <1981>. ¿ American Geophysical Union 1989